I just finished porting ecasound to Compaq's iPAQ 3600, running the
Familiar v0.5.1 Linux distribution. This is probably the first multitrack
recording suite running on a PDA. :)

Porting work was actually quite easy. Just get the arm-linux
cross-compilation environment (gcc+glibc), fetch ecasound sources from
CVS, and then compile with "./configure --disable-ncurses; make". Thanks
to auto-tools, that's all to it.

Unfortunately, as iPAQ's ARM doesn't have an FPU, ecasound runs awfully
slow. To make realtime operation possible, you need to compile with
-msoft-float (otherwise kernel will handle float operations via trapping).
Even then performing any kind of realtime effect processing is too heavy
for the ARM. But simple full-duplex capture+recording, with low-latency
settings (running with sched_fifo) works nicely without any hacks to the
kernel or Familiar distro.

But, but, until someone makes a fixed-point version of ecasound, I'm
afraid using iPAQ as your studio's central server will not be possible.;D